'06 pacifica: coolant frothy/system over pressurized?

QuestionEdit

I noticed another person having this same situation with radiator

I have this milky looking foaming water at the reservoir what is possibly causing this? and the top hose seems to have high pressure, a while back I changed the thermostat seem to be fine for quite some time then one day the top hose just came off not sure what causes that it been heating up not sure if I have a cracked head gasket or what it could be?I checked oil and it seems to be fine. no water or milky look. Does the pcv valve have anything to do with water system? please help.

AnswerEdit

Hi David, There is no connection between the pcv and the cooling system. The fact that the oil is fine show that there is no leak between the cooling and the oil systems. I suspect that you do have a head gasket leak between one of the combustion chambers and an an adjacent cooling passageway which is presurizing the cooling system and causing the hose to blow and the coolant to be frothy. A radiator shop can verify that with an exhaust gas detector they attach at the coolant bottle. Other symptoms would be excessive white smoke coming out the exhaust pipe when you start the engine from cold in the morning as well as the onset of bubbling sounds coming from the upper part of the engine early-on after starting, sooner than would be due to the cooling system reaching the boiling point of the coolant. You could first try adding Bar's Leak cooling system sealer to the cooling system to attempt to close off the leak. If that doesn't cur it, if by chance the leak was not due to a frank tear in the gasket but rather due to the cylinder head bolts being below torque spec, then you would possibly correct such a leak by loosening the bolts one half a turn on the cylinder bank that has the leak, then retighten the bolts to spec in the proper pattern. I have had success with that sort of a leak. You would need to pull all the spark plugs to find one that is 'wet', then re-do the torque on the head bolts of that bank of cylinders. Please 'rate' my answer (see below). Thanks, Roland